Atomically Controlled Electrochemical Deposition and Dissolution of Noble Metals

Abstract

The sections in this article are Introduction Atomically Controlled Deposition of Noble Metals Platinum Palladium Rhodium Ruthenium Atomically Controlled Dissolution of Noble Metals Palladium Gold Summary Acknowledgment

Multilayered Nanoclusters of Platinum and Gold: Insights on Electrodeposition Pathways, Electrocatalysis, Surface and Bulk Compositional Properties

“…21 Typical electrochemical methods being exploited in synthesis and fabrication of platinum-based nanostructured systems include galvanostatic or potentiostatic routes, where the underlying nanostructures are tuned by the nature of variation of the applied deposition current or potential with deposition time; in these processes electrons and energy required to drive the deposition reactions are generated by an external source. [22][23][24][25][26][27][28] In particular, potentiostatic routes can further be categorized as involving: (i) Overpotential Deposition (OPD), where a potential E M z+ /M is applied to a conductive substrate to drive reductive reaction, nucleation and growth of a solid metal phase from its corresponding metal ions, effectively with E M z+ /M more negative than the equilibrium potential, E eq , of the underlying reaction; and (ii) Underpotential Deposition (UPD) whereby deposition of adatoms of a metal takes place on a foreign metal substrate at potentials that are more positive than E eq of the metal ion deposition on its own metal surface, typically producing sub-monolayer to monolayer phases of the metal. 29,30 Moreover, spontaneous deposition of noble metals such as ruthenium or platinum may proceed on appropriate electrodic substrates without any utilization of an external current to achieve reduction of metal ions (This method forms part of deposition techniques generally referred as Electroless Deposition in which case the reducing equivalents required are characteristically inherent on the surfaces of the substrates used).…”

Electrochemical Detection of Tenofovir through Quenching of Chloride Ion-Mediated Gold Electrodissolution

“…The magnitude and breadth of the cathodic peak are greater when TNF is absent in the solution. The cathodic peak was attributed to the reduction of surface Au 2 O 3 and the redeposition of the [AuCl 2 ] − and [AuCl 4 ] − dissolved species that were formed during the forward scan. − In the presence of TNF, the gold electrodissolution is suppressed during the forward scan; thus, the cathodic contribution during the backward scan is only due to the reduction of surface gold oxide, hence the smaller magnitude (see Figure A and Supporting Information, Figure S1).…”